why people tend to keep doing things.

There is saying which says, "Old habits are hard to break". I guess this is true for people who are so much into smoking, drinking, and other unhealthy activities. People are said to be hedonistic, pleasure seeker. It could be that these habits give them pleasure, although temporary. Sometimes, it takes will and determination to quit unpleasant habits.

Well,such things only prove that bad habits are hard to break. I think it has become more of a ritual to your friend. He can't stand a day without smoking. I have an uncle who smokes and drinks a lot. He knows that they're bad for his health but he can't really put a stop it. Sometimes he says, "Oh well, we'll end up dying anyway."

They may want to stop bad habit but there willpower is weak and the addiction has a strong grip. They may think that somehow they will get away with it and nothing is going to happen to them. The bad habit is giving them pleasure and they will worry about the consequences later. They will stop, maybe someday but not today.

Well these types of things are either acquired bad habits (such as being lazy/sleeping in etc) or addictions (smoking, etc). I smoke.. and am most definitely addicted to it. I've tried in the past to quit but without success. The truth is your friend COULD quit smoking if he really wanted to but it takes a lot of will power and physical endurance. But anyone could quit if the motivation and effort are there. It's a choice, though. A lot of people pick the easy way out instead of stressing about it - by continuing their learned (bad) habits and giving into their addictions. It's not that we don't KNOW that it's bad for us - whatever it is that we do (believe me, smokers do NOT like when non-smokers remind us about how bad cigs are for our health.. we KNOW.)

The thing i do is probably eat to much junk food when i shouldnt, and i shouldnt eat so much chips and dip but i know its good and it sbetter then other things to eat, im not a fan of eating healthy food all the time unless i cook it and make it my own way and the way i like it. I dont smoke or drink just eat alot of junk food, even though i only weigh around 120 i know i should be more healthier and probably exercise some more but then again the food is yummy.